1. Field of the Invention
This invention relates to a bus bar-connecting structure adapted to be received in an electric connection box.
2. Description of the Related Art
An electric connection box is used for branch connection of an automobile wire harness or the like to various electric equipments, and serves to provide one centralized branch connection point so as to effect the branch connection of wiring in a rational and economical manner. With a high-density design of wire harnesses, there have now been developed various types of electric connection boxes designed respectively for various kinds of automobiles and various uses.
With respect to bus bars to be received in such an electric connection box, a plurality of kinds of bus bars are blanked from a hoop material with a press dies, and tab terminals are formed on each bus bar by stamping a pattern portion thereof, and the bus bars are arranged in layers, with an insulating plate interposed between the adjacent layers of bus bars, and this bus bar structure is received in the electric connection box.
However, the pattern portions of these bus bars are different in shape, and therefore the bus bars need to be blanked with their respective exclusive-use press dies, and therefore the production cost is high, And besides, even in the electric connection box for the same kind of automobile, the pattern portions of the bus bars vary in shape, depending on the grade of the automobile, and this has invited a problem that the general-purpose ability can not be obtained.
Therefore, the Applicant of the present application has earlier proposed a bus bar-connecting structure (see JP-A-11-180649) in which vertical bus bars (arranged in columns) are arranged on one side of an insulating plate while horizontal bus bars (arranged in rows) are arranged on the other side of the insulating plate, and indent portions of the bus bars, disposed at least on one of the opposite sides of the insulating plate, are fitted into through holes in the insulating plate at selected ones of intersection portions of the bus bars disposed on the opposite sides of the insulating plate, and each of the indent portions is held in contact with the opposed bus bar, and is welded thereto, thereby electrically connecting the bus bars, disposed on the one side of the insulating plate, to the bus bars on the other side.
In this conventional technique, it is only necessary to arrange the common straight vertical and horizontal bus bars in a combined manner and then to weld the indent portions at those intersection portions at which the upper layer of bus bars and the lower layer of bus bars are to be connected together. Therefore, in contrast with the conventional structure, it is not necessary to blank the bus bars into different pattern shapes with exclusive-use press-dies, and therefore the production cost is reduced. And besides, by changing the positions of the indent portions, the bus bar-connecting structure can meet any pattern configuration of the bus bars, and therefore the time and labor, required for the design of a circuit, can be greatly reduced, and besides a design change, necessitated by a slight circuit change, can be rapidly dealt with, thus achieving an advantage that the general-purpose ability is enhanced.
This invention is directed to an improvement over the above bus bar-connecting structure proposed by the Applicant of the present application, and an object of the invention is to provide a bus bar-connecting structure which can be produced at a lower cost, and has an excellent general-purpose ability.
In order to achieve the above object, the present invention provides a bus bar-connecting structure for being received in an electric connection box, CHARACTERIZED in that:
vertical bus bars are arranged on one side of an insulating plate at a predetermined pitch, and extend straight in a vertical direction while horizontal bus bars are arranged on the other side of the insulating plate at a predetermined pitch, and extend straight in a horizontal direction; and through holes are formed respectively through those portions of the insulating plate, disposed respectively at intersection portions of the vertical bus bars and the horizontal bus bars provided on the opposite sides of the insulating plate; and a laser beam is applied to the bus bars, disposed on one of the opposite sides of the insulating plate, at selected ones of the intersection portions, so that each laser beam-applied portion of the bus bars is melted, and flows through the through hole, and is fused to the mating bus bar on the other side of the insulating plate, and the bus bars, disposed on the opposite sides of the insulating plate, are electrically connected together.
In the invention, the vertical bus bars are arranged on the one side of the insulating plate while the horizontal bus bars are arranged on the other side of the insulating plate, and a laser beam is applied to the bus bars, disposed on one of the opposite sides of the insulating plate, at selected ones of the intersection portions, so that each laser beam-applied portion of the bus bars i smelted, and flows through the through hole, and is fused to the mating bus bar on the other side of the insulating plate, and the bus bars, disposed on the opposite sides of the insulating plate, are electrically connected together.
Selected ones of the intersection portions of the bus bars are removed. With this construction, the bus bars-, arranged in the same layer, are electrically disconnected from each other, thereby providing independent circuits.